Electrical Problems in the 1990 C4?

Hello all!

I have a 1990 C4 and have noticed that the interior lights stay on (indefinitely on occasion) after the car is turned off and keys are taken out of the ignition. Although this has yet to result in any battery or starting problems, there is a definite electrical issue and they stay on for 15-20 minutes at the minimum, not the customary exit time on most cars.

I am an automotive engineer - GM specific - so I understand the ins and outs of most GM cars, but this problem is beyond my area of expertise. Sheet metal, interior/cock-pit, and Powertrain are my areas... this is confusing to both me and my friends.

Any advice would be appreciated! Has anyone else experienced this?




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Possibly a contaminated door switch, out of adjustment or mis aligned.
It also could be a timed door relay which keeps the interior lights on for a short period of time after you exit your car.

See tech manual for relay location.